Electrosurgical system with electrically active outer surface

ABSTRACT

An electrosurgical system may include a medical delivery device and an electrosurgical device to perform an electrosurgical procedure. The electrosurgical device may have a monopolar configuration. An outer surface of the medical delivery device may include a conductive portion that is part of a return path for a bipolar configuration. Current may be supplied through an active member of the electrosurgical device to perform the procedure. After passing through tissue, the current may be drawn to the electrode portion of the medical delivery device to complete the circuit.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/798,262, filed Mar. 15, 2013. The contents of U.S. ProvisionalApplication No. 61/798,262 are incorporated by reference in theirentirety.

TECHNICAL FIELD

The present invention relates generally to medical devices, and moreparticularly to electrosurgical medical devices and systems.

BACKGROUND

Electrosurgery may include the application of high frequency electricalcurrent to biological tissue at a treatment to perform an operation onthe tissue, such as cut or coagulation. Endoscopes may be used toprovide visualization of the treatment site to an operator or physicianperforming the electrosurgery. The endoscope may include a lumen orchannel that is sized for advancement of an electrosurgical device toperform the electrosurgical procedure.

BRIEF SUMMARY

The present description describes systems, devices, and methods toperform electrosurgical procedures. In a first aspect, a bipolarelectrosurgical system configured to perform an electrosurgicalprocedure at a treatment site within a patient may include anelectrosurgical device; and a medical delivery device configured todeliver a distal end of the electrosurgical device to the treatmentsite. The electrosurgical device may include an active member that isconfigured as part of an active path for the bipolar electrosurgicalsystem. In addition, the medical delivery device may include aconductive portion that is at least one of disposed on or integral withan outer surface of the medical delivery device. The conductive portionmay be configured as part of a return path for the bipolarelectrosurgical system.

In a second aspect, a method of performing an electrosurgical procedureusing a bipolar configuration may include: delivering an outer tubularmember of a medical delivery device to a treatment site within apatient. The medical delivery device may include a conductive portionthat is at least one of disposed on or integrated with an outer surfaceof the tubular member the medical delivery device. The medical deliverydevice may also include a working channel longitudinally extendingwithin the outer tubular member of the medical delivery device. Themethod may also include contacting a return electrode to a first tissueportion of the patient when a distal portion of the medical deliverydevice is positioned at the treatment site; and delivering anelectrosurgical device within the working channel of the medicaldelivery device to the treatment site. The electrosurgical device mayinclude an inner tubular member and an active member disposed within theinner tubular member. In addition, the method may include contacting adistal end of the active member of the electrosurgical device with asecond tissue portion. Also, the method may include electricallycoupling the active member of the electrosurgical device to an activeport of a power source; electrically coupling the conductive portion ofthe medical delivery device to a return port of the power source; andactivating the power source to supply electrical current to thetreatment site.

In a third aspect, a bipolar electrosurgical system is configured toperform an electrosurgical procedure at a treatment site within apatient. The bipolar electrosurgical system may include an active memberelectrically coupled to an active port of a power source and an innertubular member, where the active member movably disposed andlongitudinally extending within the inner tubular member. The bipolarelectrosurgical system may also include an outer tubular member; and aworking channel lumen longitudinally extending within a body of theouter tubular member, where the active tubular member and the innertubular member are movably disposed within the working channel lumen.The system may also include a conductive portion that is one of disposedon or integrated with an outer surface of the outer tubular member, andwhere the conductive portion is electrically coupled to a return port ofthe power source.

In a fourth aspect, an endoscope is configured to operate in a bipolarelectrosurgical system. The endoscope may include an elongate tubularmember having an outer surface. The endoscope may also include a workingchannel lumen longitudinally extending within the elongate tubularmember. The working channel lumen may be configured to have anelectrosurgical device movably disposed within it; and at least oneillumination lumen having illumination fibers disposed within it. Theillumination fibers may be configured to illuminate a treatment site forvisualization using the endoscope. The endoscope may also include aconductive portion that at least one of is disposed on or integral withthe outer surface of the elongate tubular member. The conductive portionmay be configured for contact with tissue to perform an electrosurgicalprocedure using a bipolar configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional side view of a medical system thatincludes a bipolar electrosurgical system.

FIG. 2 shows a cross-sectional side view of an alternative embodiment ofa distal portion of the bipolar electrosurgical system shown in FIG. 1.

FIG. 3 shows a cross-sectional side view an alternative embodiment of amedical system that includes a bipolar electrosurgical system.

FIG. 4 shows a cross-sectional side view of a sleeve disposed on adistal portion of an outer surface of a medical delivery device.

FIG. 5 shows a cross-sectional side view of a cap disposed on a distalportion of an outer surface of a medical delivery device.

FIG. 6 shows a conductive portion integrated with an outer surface of amedical delivery device.

FIG. 7 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 1, showing acircumferential orientation of a conductive portion.

FIG. 8 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 1, showing an alternativecircumferential orientation of the conductive portion.

FIG. 9 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 1, showing anotheralternative circumferential orientation of the conductive portion.

FIG. 10 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 1, showing a return wiredisposed within a tubular member of a medical delivery device.

FIG. 11 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 1, showing an alternativeconfiguration of the return wire disposed within the tubular member ofthe medical delivery device.

FIG. 12 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 1, showing anotheralternative configuration of the return wire disposed within a tubularmember of a medical delivery device.

FIG. 13 shows a cross-sectional axial view of the distal portion of thebipolar electrosurgical system shown in FIG. 3, showing a return wiredisposed outside of a tubular member of a medical delivery device.

FIG. 14. shows a side view of the distal portion of the bipolarelectrosurgical system of FIG. 1, 2 or 3, where the return path is asingle return path.

FIG. 15. shows a side view of an alternative embodiment of the distalportion of the bipolar electrosurgical system of FIG. 1, 2 or 3, wherethe return path includes two return paths and where a gap separating twoconductive portions extends in a substantially straight direction.

FIG. 16. shows a side view of a second alternative embodiment of thedistal portion of the bipolar electrosurgical system of FIG. 1, 2, or 3,where the return path includes two return paths and where the gap has azig-zag pattern.

FIG. 17. shows a side view of a third alternative embodiment of thedistal portion of the bipolar electrosurgical system of FIG. 1, 2, or 3,where the return path includes two return paths and where the gap has asinusoidal pattern.

FIG. 18 shows a cross-sectional side view of a medical system that isconfigured to perform two electrosurgical procedures using monopolarconfigurations.

FIG. 19 shows a treatment site within a patient and an electrosurgicalsystem at the treatment site to perform an electrosurgical procedure.

DETAILED DESCRIPTION

The present disclosure describes various embodiments of anelectrosurgical system that is configured to perform electrosurgicalprocedures at treatment sites within a patient. The electrosurgicalsystem may include three elongate members—an elongate active member, anelongate inner tubular member, and an elongate outer tubular member. Thethree elongate members may be parts or components of two differentmedical devices making up the system. The elongate active member and theelongate inner tubular member may be components of an electrosurgicaldevice that is configured to supply electrical current to the treatmentsite to perform the electrosurgical procedure. The elongate outertubular member may be a component of a medical delivery device that isconfigured to provide a pathway, such as a channel or a lumen, extendingfrom outside of the patient to the treatment site for delivery of theelectrosurgical device to the treatment site.

To conduct current to perform an electrosurgical procedure, theelectrosurgical system may be used to form an electrical circuit thathas an active path and a return path in electrical communication withtissue at the treatment site. The tissue may function as a load due toits resistive properties. The active path, the return path, and thetissue, together may form the electrical circuit, through which thecurrent may be conducted. Typically, the active path and the return pathare connected to a power source, such as an electrosurgical unit (ESU),that is configured to supply the electrical current through the circuit.The power source may supply the current through the active path, and thecurrent may be returned back to the power source through the returnpath.

The electrosurgical system may have a monopolar or a bipolarconfiguration to perform various electrosurgical procedures. For amonopolar configuration, the active path may include one or moreconductive portions of the electrosurgical system extending within thepatient to the treatment site and contacting the tissue. The return pathmay be external to the patient. In particular, the return path may useor include a neutral electrode, which may be a solid, neutral electrode,or a split neutral electrode, and which may be positioned external tothe patient undergoing the electrosurgical procedure, such as on thethigh of the patient. The return path, which may include a wire or acable, may extend external to the patient and have one end connected tothe neutral electrode and another end connected to a power source. Toperform an electrosurgical procedure with a monopolar configuration, thepower source may supply current through the active path to the tissue,where the current then flows to the neutral electrode and through thereturn path back to the power source.

For a bipolar configuration, the active path may be similar to an activepath for a monopolar configuration. However, the return path for abipolar configuration may differ from a monopolar in that, like theactive path, the return path may contact the tissue and include one ormore portions of the electrosurgical system extending within thepatient. For some configurations, the active path and the return pathmay extend generally parallel to each other within the patient. Toperform an electrosurgical procedure with the bipolar configuration, thepower source may supply current through the active path to the tissue,where the current may flow to a return electrode contacting the tissueinternal to the patient at the treatment site. The current may then flowthrough a return path extending within the patient back to the powersource.

The electrosurgical system may include an outer surface that has aportion that is conductive. The conductive portion of the outer surfacemay be configured to be part of either the active path or the returnpath. For configurations where the conductive portion is part of thereturn path, the electrosurgical system may have a bipolarconfiguration. Current may be supplied through the active membercontacting the tissue. The current may then flow to the conductiveportion of the outer surface, which may also be contacting the tissueand which may be or function as a return electrode for the return path.

For configurations where the conductive portion is part of the activepath, the electrosurgical system may have a monopolar configuration. Formonopolar configurations, the electrosurgical system may be configuredto perform two different electrosurgical procedures, such as a cutprocedure and a coagulation procedure, both of which may be performed ina monopolar manner. For the cut procedure, electrical current may besupplied to the active member to cut tissue at the treatment site. Thecurrent may then flow outside of the patient to the neutral electrodeand back to the power source. During the cut procedure, the activemember may be electrically connected to the power source, while theconductive portion may be electrically disconnected from the powersource. For the coagulation procedure, electrical current may besupplied through the conductive portion to coagulate tissue at thetreatment site. The current may then flow outside of the patient to theneutral electrode. During the coagulation procedure, the conductiveportion may be electrically connected to the power source, while theactive member may be electrically disconnected from the power source. Aswitch may be used to switch the electrical connections between theactive member and the conductive portion.

The electrical surgical device comprised of the active member and thetubular inner member may be any type of electrosurgical deviceconfigured to perform an electrosurgical procedure in a monopolarmanner. Example electrosurgical devices may include a sphinctertome, anendoscopic needle knife, or forceps, as examples. Other electrosurgicaldevices may be included. The active member may be made of a conductivematerial, such as stainless steel or tungsten, and may be configured todeliver the electrical current to the treatment site. The active membermay be disposed within a lumen of the inner tubular member. The innertubular member, such as a catheter, may be made of an insulatingmaterial, such as fluoropolymer materials, includingpolytetrafluoroethylene (PTFE) or perfluoroalkoxy (PFA), or othermaterials such as polyethylene, nylon, or fluorinated ethylene, asexamples. The combination of the active member and the inner tubularmember may form a monopolar configuration in that the return path is notattached to, integrated with, disposed within, or included as part ofthe inner tubular member. Instead, to perform an electrosurgicalprocedure using the active member and the inner tubular member, theelectrical current may be supplied through the active member, and may bereturned using a neutral electrode outside the patient.

Alternatively, when the active and inner tubular members are used withthe outer tubular member, the neutral electrode may be excluded and theelectrosurgical procedure may be performed in a bipolar manner becausethe return path may be attached to, integrated with, disposed within, orincluded as part of the outer tubular member. In this way, while theactive member and inner tubular member may be a monopolarelectrosurgical device, the electrosurgical system as a whole may bebipolar.

The outer tubular member may be any medical device that may beconfigured to provide a pathway, such as a channel or a lumen fromoutside of the patient to the treatment for delivery of the active andinner tubular members (i.e., the monopolar electrosurgical device) tothe treatment site. An example outer tubular member may be an endoscopethat includes a working or accessory channel configured and/or sized tomove an electrosurgical device to and from the treatment site.

FIG. 1 shows a partial cross-sectional side view of a medical system 100that includes an example electrosurgical system 102 configured toperform one or more electrosurgical procedures. The exampleelectrosurgical system 102 may include an endoscope 104 and anelectrosurgical device 106. The endoscope 104 may be a medical devicethat uses a visualization system, including a light delivery system anda lens system, to capture visual images of a treatment site within apatient. The endoscope 104 may include an elongate tubular member 108that extends from a proximal portion 110 to a distal portion 112. Thetubular member 108 may be considered an outer tubular member of theelectrosurgical system 102. The outer tubular member 108 may be insertedinto an opening or an incision of the patient and distally moved withinthe patient until the distal portion 112 is positioned at the treatmentsite.

The endoscope 104 may include an accessory or working channel 114 thatmay be configured and/or sized to have the electrosurgical device 106movably disposed within it. The working channel 114 may longitudinallyextend within the tubular member 108 from the proximal portion 110 tothe distal portion 112. At or near the proximal portion 110, theendoscope 104 may include a working channel port 116, which may includean opening 118 in communication with the working channel 114.

The electrosurgical device 106 may include an elongate active member 120disposed within an elongate tubular member 122. The elongate tubularmember 122 may be an inner tubular member of the electrosurgical system102. The combination of the active member 120 and the inner tubularmember 122 may be of any monopolar configuration to perform anelectrosurgical procedure. As an example, the inner tubular member 122and the active member 120 may be an endoscopic needle knife, where theactive member is a conductive cutting wire movably disposed within alumen, such as a central lumen, of the inner tubular member 122. Otherconfigurations of the active and inner tubular member 120, 122 arepossible. As shown in FIG. 1, the electrosurgical device 106 may includea handle assembly 124 operatively coupled to the active member 120 tomove the active member 120 relative to the inner tubular member 122.

Distal ends 126, 128 of the active and inner tubular member 120, 122 maybe inserted into the opening 118 of the working channel port 116 anddistally moved within the working channel 114 to the distal portion 112,where the active and inner tubular members 120, 122 may extend from thedistal portion 112 to the proximal portion 110. At the distal portion112, the endoscope 104 may include a distal opening 130 in communicationwith the working channel 114. The distal ends 126, 128 may further bedistally advanced to exit the working channel 114 through the distalopening 130, where they may be disposed external the endoscope 104. Forsome electrosurgical devices 106, outside of the endoscope 104, thedistal end 126 of the active member 120 may be moved relative to thedistal end 128 of the inner tubular member 122, such as through use ofthe handle assembly 124, to expose the distal end 126 of the activemember 120 for contacting the tissue. For example, the distal end 126 ofthe active member 120 may be distally advanced past the distal end 128of the inner tubular member, such as for endoscopic needle knives. Asanother example, the active member 120 may be retracted to cause acurling motion at the distal ends 126, 128 to extend the distal end 126of the active member 120 away from the inner tubular member 122, such asfor sphincterotomes. Various configurations are possible.

The distal opening 130 shown in FIG. 1 is proximal a distal end 131 ofthe outer tubular member 108, which may be a configuration for a sideviewing endoscope 104. In an alternative configuration, as shown in FIG.2, the electrosurgical system 102 may include an endoscope 204 with anouter tubular member 208 that has a working channel 214 that, at adistal portion 212, extends to an opening 230 at a distal end 231.Various types of endoscopes may be used, which may depend on theelectrosurgical procedure being performed and/or the electrosurgicaldevice 106 being used to perform the electrosurgical procedure.

Referring back to FIG. 1, the active member 120 may be electricallycoupled to a power source 132, such as a radio frequency (RF) generatoror an electrosurgical unit (ESU), that is configured to supplyelectrical current to perform the electrosurgical procedure. For someconfigurations of the electrosurgical device 106, the active member 120may proximally extend to the handle assembly 124, where a proximal endof the active member 120 may be connected to a conductive pin 134 thatextends to a port 136 of the handle assembly 124. The conductive pin 134and/or the port 136 may be adaptable to connect to supply cabling 138that may be configured to connect to an active port 140 of the powersource 132.

At the distal portion 106, the outer tubular member 108 may have aconductive portion 142 disposed on an outer surface 144 of the outertubular member 108. The conductive portion 142 may serve or function asa return electrode for the electrosurgical system 102. As a returnelectrode, the conductive portion 142 may be configured to contact thetissue at the treatment site so that the electrosurgical system 102 mayperform an electrosurgical procedure using a bipolar configuration. Theconductive portion 142 may be part of a return path that also includes areturn wire 146 extending from the distal portion 112 to the proximalportion 110 of the outer tubular member 108.

A length of the conductive portion 142 may vary, depending on theconfiguration and/or the electrosurgical procedure being performed. Thelength may be determined to achieve a surface area of the conductiveportion 142 that yields or provides a desired current density ratiobetween the active member 120 and the conductive portion 142. Thecurrent density ratio may be at least three-to-one, and a ratio of atleast ten-to-one may be optimal. In addition, the conductive portion 142may be longitudinally disposed along the tubular member 108 at aposition that is at or relatively near where the active member 120 iscontacting the tissue in order to achieve the benefits of the bipolarconfiguration, such as reduced heat. For example, the active member 120and the conductive portion 142 may both contact the tissue at or nearthe distal portion 112. Conversely, if the conductive portion 142 is ata position along the outer tubular member 108 that is relatively faraway from where the active member 120 is contacting the tissue, theconfiguration between the active member 120 and the conductive portion142 may behave or function more similarly to a monopolar configuration,and the benefit of the bipolar configuration, such as reduced heat, maybe eliminated or reduced.

In some example embodiments, as shown in FIG. 1, the return wire 146 maybe disposed and extend within the tubular member 108, from the distalportion 112 to the proximal portion 110. For example, as shown in FIG.1, the return wire 146 may be disposed and extend within the workingchannel 114 from the distal portion 112 to the proximal portion 110,such as to the working channel port 116. That is, the return wire 146may be disposed within the same working channel 114 of the endoscope 104as the electrosurgical device 106. In alternative configurations, thereturn wire 146 may be disposed and extend within the tubular member 108by being disposed in a different channel or lumen other than the workingchannel, such as a irrigation channel or an air channel (not shown inFIG. 1), as examples. Alternatively, the return wire 146 may be embeddedwithin a body 147 of the outer tubular member 108. Variousconfigurations are possible.

The return wire 146 may be electrically coupled to a return port 148 ofthe power source 132. For some example configurations, a proximal end ofthe return wire 146 may be connected to a conductive pin 150, which maybe adaptable to connect to return cabling 152 that may to connect to thereturn port 148.

For configurations where the return wire 146 is disposed within theouter tubular member 108, the conductive portion 142 may be electricallycoupled to the return wire 146 in various ways. For example, as shown inFIG. 1, the conductive portion 142 may proximally extend to a conductivering or cannula 156, which may electrically couple the conductiveportion 142 to the return wire 146. In some example embodiments, theconductive cannula 156 may be attached or crimped to the outer surface144 of the outer tubular member 108. The conductive cannula 156 may bemade of metal, such as stainless steel, silver, gold, tantalum, ortungsten, as examples. A part of the conductive portion 142 may be incontact with at least a portion of the conductive cannula 156 so thatthe conductive portion 142 and the conductive cannula 156 areelectrically coupled. To electrically couple the return wire 146 withthe conductive cannula 156, the return wire 146 may be curled at itsdistal end to extend from within the working channel 114 to the outersurface 144 of the tubular member 108. The conductive cannula 156 may becrimped to the tubular member 108 over the distal end of the return wire148. In an alternative example embodiment, a gap or opening extendingfrom the outer surface 144 to the working channel 114 may include or befilled with a conductive material, such as solder, to connect the distalend of the return wire with the conductive portion. Variousconfigurations are possible.

In an alternative example embodiment, as shown in FIG. 3, anelectrosurgical system 302 may include a return wire 346 that isdisposed external or outside of the tubular member 108. The return wire346 may extend alongside the outer tubular member 108 from the distalportion 112 to the proximal portion 110, where the return wire 346 maybe electrically coupled to the return port 148 of the power source 132,such as by using a conductive pin 150 and return cabling 152, aspreviously described. At the distal portion 112, the return wire 346 maybe electrically coupled to the conductive portion 142 in various ways.For example, the conductive cannula 156 may crimp the return wire 346 tothe outer surface 144 of the tubular member 108. In addition oralternatively, the distal end of the return wire 346 may be soldered tothe conductive portion 142. For some configurations, the return wire 346may be attached or adhered to the outer surface 144 of the outer tubularmember 108 from the proximal portion 110 to the distal portion 112.Alternatively, the return wire 346 may be unattached to the outersurface 144 of the tubular member 108.

Referring to FIG. 1, 2, or 3, the conductive portion 142 may includevarious example embodiments and/or may be disposed on the outer surface144 in various ways. For example, the conductive portion may 142 mayinclude conductive ink that may be applied and/or adhered to the outersurface 144, such as by spraying, pad printing, rolling, brushing,dipping, or electroplating, as examples. Alternatively, the conductiveportion 142 may include conductive tape or conductive stickers that maybe applied and/or adhered to the outer surface 144. For these exampleembodiments, the conductive portion 142 may be fixedly attached to theouter surface 144, in that the conductive portion 142 may not bedetached from the outer surface 144 without an adhesive remover orscraping operation.

In alternative example embodiments, the conductive portion 142 may bedisposed on the outer surface 144 of the tubular member 108 by beingpart of a removably attachable electrode that may be disposed about theouter surface 144 of the distal portion 112. An example removablyattachable electrode may include a sleeve 460, as shown in FIG. 4. Aconductive portion 442 may be disposed on an outer surface 462 of thesleeve 460. The conductive portion 442 may include any of a variety ofconductive materials, such as conductive ink, conductive tape,conductive stickers, or plurality of wires, such as a weaved arrangementof wires or a mesh network of wires. Various configurations arepossible. An inner surface 464 of the sleeve 460 may form a friction fitwith the outer surface 144 of the tubular member 108.

The sleeve 460 may be attached to the outer surface 144 in various ways.For example, the sleeve 460 may be proximally pulled from the distal end131 by sliding the sleeve 460 over the outer surface 144. Alternatively,the sleeve 460 may include a finger cot or condom-type device that isrolled and expanded over the outer surface 144 to a desired position atthe distal portion 112.

As shown in FIG. 4, a return wire 446 may be electrically coupled to theconductive portion 442. For example, the return wire 446 may be solderedto the conductive portion 442, or may be crimped to the conductiveportion 442, such as by using the conductive cannula (FIG. 1). Variousconfigurations are possible. From the position where the return wire 446is coupled to the conductive portion 442, the return wire 446 mayproximally extend alongside the outer surface 144 of the endoscope asshown in FIG. 4, or alternatively, may extend to within the outertubular member 108 as shown in FIG. 1 or 2.

An alternative removably attachable electrode may include a cap or anend cap 560, as shown in FIG. 5, that may be disposed about the outersurface 144. Similar to the sleeve 460, a conductive portion 542 may bedisposed on an outer surface 562 of the cap 560. An inner surface 564 ofthe cap 560 may form a friction fit with the outer surface 144 of thetubular member 108. For example, the inner surface 564 may includeand/or be coated with a silicone or rubber based material to createfriction with the outer surface 144. Also, similar to the sleeveconfiguration 460, a return wire 546 may be electrically coupled to theconductive portion 542, where the return wire 546 may proximally extendalongside the outer surface 144 as shown in FIG. 5, or alternatively,may extend to within the outer tubular member 108 as shown in FIG. 1 or2.

The various embodiments of the conductive portion 142 may be used with,integrated with, applied to, and/or disposed on outer surfaces ofendoscopes or other similar types of medical delivery devices, eithercurrently existing or later developed, that do not include conductiveportions. In addition, at least some of the embodiments of theconductive portion 142, such as the sleeve 460 or the cap 560, may beattached and then removed to and from the outer surface 144 of theendoscope 104 before or after the electrosurgical procedure isperformed.

In alternative example embodiments, instead of being disposed on theouter surface 144 of the outer tubular member 108, a conductive portion642 may be integral with, part of, or built into the outer surface 144,as shown in FIG. 6. For some configurations, an outer surface 644 of theconductive portion 642 may be flush or even with the outer surface 144of the tubular member 108. Alternatively, the conductive portion 642 mayprotrude from the outer surface 144 of the outer tubular member 108.

Although not shown in FIGS. 1-6, the endoscope 104 may include aplurality of lumens or channels, other than the working channel 114,extending within the tubular member 108 from the proximal portion 110 tothe distal portion. FIG. 7 shows a cross-sectional view of an exampleembodiment of the electrosurgical system 102 taken along line 7-7 inFIG. 1. As shown in FIG. 7, in addition to the working channel 114, theendoscope 104 may include an air lumen 170, an irrigation lumen 172, andone or more channels 174 for visualization, such as for illumination orimaging fibers or cables. More lumens or fewer lumens may be included.

The conductive portion 142 may be circumferentially disposed at leastpartially around the outer surface 144 of the tubular member 102. Forexample, as shown in FIG. 7, the conductive portion 142 may be disposedabout 180 degrees around the outer surface 144. Alternatively, theconductive portion 142 may be disposed less than or greater than180-degrees. For example, as shown in FIG. 8, the conductive portion 142may be circumferentially disposed completely (i.e., 360-degrees) aroundthe outer surface 144. The circumferential disposition may depend on asurface area to achieve a desired current density ratio between theactive member 120 and the conductive portion 142, which may be at leastthree-to-one, as described above. The surface area may be determined bythe length and circumferential width of the conductive portion 142.

In general, the conductive portion 142 may have a circumferentialdisposition that is most likely to make contact with the tissue at thetreatment site, which may vary depending on the electrosurgicalprocedure and/or the area of the body. In some example configurations,the circumferential disposition may be determined relative to adirection in which the electrosurgical device, including the activemember 120 and/or the inner tubular member 122, protrudes or radiallyextends from the outer tubular member 108. For example, as shown in FIG.7, a central position 143 of the conductive portion 142 may be alignedor substantially aligned with a radial direction in which the ends 126,128 of the active and inner tubular member 120, 122 extend out of theopening 130 (FIG. 1), as identified by the dotted line 145.Alternatively, as shown in FIG. 9, a central position 143 may be offsetby a predetermined number of degrees from a radial direction in whichthe ends 126, 128 extend.

FIG. 10 shows an axial cross-sectional view of an example embodiment ofthe electrosurgical system 102 taken along line 10-10 in FIG. 1. Thecross-sectional view shown in FIG. 10 may be representative of the axialcross-section of the outer tubular member 108 proximal the conductiveportion 142. FIG. 10 shows both the return wire 146 and theelectrosurgical device 106 (i.e., the active member 120 and the innertubular member 122) disposed in the working channel 114. In analternative example configuration of the electrosurgical system 102shown in FIGS. 1 and 10, the return wire 146 may be disposed within thetubular member in a different portion or area than the working channel114. For example, as shown in FIG. 11, the return wire 146 may bedisposed in the air lumen 170 or the irrigation lumen 172.Alternatively, as shown in FIG. 12, the return 146 wire may be embeddedwithin the body 147 of the outer tubular member 108.

FIG. 13 shows a cross-sectional view of an example embodiment of theelectrosurgical system 302 taken along line 13-13 in FIG. 3. Thecross-sectional view shown in FIG. 13 may be representative of thecross-section of the outer tubular member 108 proximal the conductiveportion 142. As shown in FIG. 13, the return wire 346 may be disposedexternal to or outside of the outer tubular member 108.

In some example embodiments, the return path may include a single returnpath. For these example embodiments, the conductive portion may includea single, continuous portion electrically coupled to a single returnwire. FIG. 14 shows a side view of an example embodiment of the distalportion 112, such as the distal portion 112 shown in FIG. 3, from anangle showing most if not all of the conductive portion 142 coupled to asingle return wire 346.

In alternative example embodiments, the return path may include multiplereturn paths, such as two return paths. The two return paths may beelectrically isolated or substantially electrically isolated from eachother. Two return paths may be included to provide a safety feature foruse with the power source 132, which may be configured to prevent outputof the electrical current unless each of the return paths are in contactwith the tissue.

FIG. 14 shows a side view of an example embodiment of the distal portion112 shown in FIG. 3 from an angle showing most if not all of theconductive portion 142, where the return path includes a dual returnpath. To form the dual return path, the conductive portion 142 mayinclude two sub-portions or strips, including a first sub-portion 1442 aand a second sub-portion 1442 b. The first sub-portion 1442 a and thesecond sub-portion 1442 b may be electrically isolated from each other.A gap or spacing 1460 in between the first and second sub-portions 1442a, 1442 b may electrically isolate the first and second sub-portions1442 a, 1442 b from each other. As shown in FIG. 14, the first andsecond sub-portions 1442 a, 1442 b may each be electrically coupled to arespective return wire 1446 a, 1446 b. The two return wires 1446 a, 1446b may each extend proximally external to and alongside the tubularmember 108 to the proximal portion 110. Alternatively, one or more bothof the return wires 1446 a, 1446 b may extend to within the tubularmember 108, as described above with reference to FIG. 1.

In one example configuration, as shown in FIG. 15, the gap 1560separating and electrically isolating the first and second sub-portions1542 a, 1742 b may longitudinally extend along the outer surface of thedistal portion 112 in a straight or substantially straight direction. Inalternative configurations, the gap may longitudinally extend in anon-straight manner. For example, as shown in FIG. 16, a gap 1660 mayhave a zig-zag pattern. As another example, referring to FIG. 17, thegap 1760 may have a sinusoidal pattern. Various other patterns may beused for the gap, such as helical or spiral, as examples. Alternatively,the gap may not necessarily have a pattern, but may extend in agenerally non-straight manner along the outer surface 144 of the distalportion 144. Configuring the gap to extend in a non-straight manner orhave a non-straight pattern may be advantageous over configurationswhere the gap extends straightly in that the non-straight configurationsmay facilitate contact for both the first and second sub-portions of theconductive portion with the surrounding tissue.

FIG. 18 shows an alternative example embodiment of an electrosurgicalsystem 1802 that may include an endoscope 1804 and an electrosurgicaldevice 1806. The electrosurgical system 1802 may be configured toperform two electrosurgical procedures both using a monopolarconfiguration. A first electrosurgical procedure may be performed withan active member 1820 of the electrosurgical device 1806, and a secondelectrosurgical procedure may be performed with a conductive portion1842 disposed or integrated with an outer surface 1844 of an outertubular member 1808 of the endoscope 1804. An example first proceduremay be a cut procedure and an example second procedure may be acoagulation procedure, although other procedures may be used. For theexample configuration shown in FIG. 18, the active member 1820 and theconductive portion 1842 may be alternatingly part of the active path.

The electrosurgical system 1802 may include or use a switch 1880 thatalternatingly connects an active port 1840 of a power source 1832 witheither the active member 1822 or the conductive portion 1842. As shownin FIG. 18, the switch 1880 may include an input 1882 that iselectrically coupled to the active port 1840. That switch 1880 may alsoinclude a first output 1884 that is electrically coupled to a proximalend of the active member 1822 and a second output 1886 that iselectrically coupled to a proximal end of a wire 1846. A return port1848 may be electrically coupled to a neutral electrode (now shown) fora monopolar configuration.

To perform the first electrosurgical procedure, the switch 1880 may bepositioned in a first state or position so that the active port 1840 iselectrically coupled to the active member 1822, and the conductiveportion 1842 is electrically disconnected from the active port 1840. Thepower source 1832 may be activated, which may supply electrical currentto the active member 1822 to perform the first electrosurgicalprocedure. For the monopolar configuration, the current may flow to theneutral electrode and back to the return port 1848 of the power source1832.

To perform the second electrosurgical procedure, the switch 1880 may bepositioned in a second state or position so that the active port 1840 iselectrically coupled to the conductive portion 1832 of the outer surface1844 of the endoscope 1804, and the active member 1822 is electricallydisconnected from the active port 1840. In some situations, the distalportion 1812 may be repositioned so that the conductive portion 1842 maycontact the tissue to perform the second electrosurgical procedure. Thepower source 1832 may be activated, which may supply electrical currentthrough the wire 1846 to the conductive portion 1842 to perform thesecond electrosurgical procedure. For the monopolar configuration, thecurrent may flow to the neutral electrode and back to the return port1848 of the power source 1832.

The present description also describes a method of operation of abipolar electrosurgical system to perform an electrosurgical procedureat a treatment site within a patient. Reference is made to FIG. 19,which shows an example bipolar electrosurgical system 1902 performing asphincterotomy to access a bile duct 1980, although similar operationmay be performed for other electrosurgical procedures at other areaswithin the patient. The bipolar electrosurgical system 1902 may includea side viewing endoscope 1904 and an electrosurgical device 1906configured to perform a sphincterotomy and/or cut a sphincter muscle.The electrosurgical device 1906 may be a monopolar device. In theexample embodiment shown in FIG. 19, the electrosurgical device 1906 isan endoscopic needle knife that includes a catheter and a cutting wiredisposed within the catheter. However, the electrosurgical device 1906may be a sphincterotome in alternative embodiments.

To perform the sphincterotomy, the endoscope 1904 may be inserted intothe patient, through the esophagus 1982 into the stomach 1984. Theendoscope 1904 may further be distally moved through the pylorus 1988into the duodenum 1988, where a distal portion 1912 may be positioned toaccess the bile duct 1980. The side viewing endoscope 1904 may includean opening 1930, which may be positioned to face a papillae 1990, whichprovides an opening to the bile duct 1980. The endoscope 1904 mayinclude a visualization and/or camera system 1905 to provide or enablevisualization of the treatment site.

The endoscope 1904 may include a conductive portion 1942 disposed on orintegrated with an outer surface 1944 of the endoscope 1904. The distalportion 1912 of the endoscope 1904 may be positioned so that theconductive portion 1942 contacts an inner wall 1992 of the duodenum1988.

As shown in FIG. 19, for some example configurations of the endoscope1904, the conductive portion 1942 may have a length that is sufficientto proximally extend in the duodenum 1988 and up to and/or past thepylorus 1986 into the stomach 1984 when the endoscope 1904 is inposition to perform the sphincterotomy. The endoscope 1904 may bepositioned so that the conductive portion 1942 is also and/oralternatively in contact with an inner wall 1994 of the pylorus 1986.The pylorus may be generally constrictive in nature, and so when theendoscope 1904 is positioned in the duodenum 1988, the pylorus 1986 maysqueeze or constrict around the outer surface 1944 of the endoscope1904. As such, by configuring the conductive portion 1942 to have asufficient length to proximally extend to and/or past the pylorus 1986when the endoscope 1904 is in position for the sphincterotomy to beperformed, even if the conductive portion 1942 does not sufficientlycontact the inner wall 1992 of the duodenum 1988, sufficient contactbetween the conduct portion 1942 and the overall tissue may be ensuredor an increased likelihood of the contact may exist because of thelikelihood of contact between the conductive portion 1942 and the innerwall 1994 of the pylorus 1986 due to the constrictive nature of thepylorus 1986.

In addition, as shown in FIG. 19, a return wire 1946 may be electricallycoupled to the conductive portion 1942. In the example embodiment shownin FIG. 19, the return wire 1946 may extend external to and alongsidethe endoscope 1904, similar to the configuration shown in FIG. 3.Alternatively, the return wire 1946 may extend to within the endoscope1904.

When the endoscope 1904 is in position within the duodenum 1988, theendoscopic needle knife 1906 may be distally advanced within a workingchannel of the endoscope 1904 (as shown in FIGS. 1-13). The endoscopicneedle knife 1906 may be distally advanced through the distal portion1912 to the opening 1930 of the endoscope 1904. Distal ends 1926, 1928of the cutting wire and catheter, respectively, may be advanced throughthe opening 1930 until they are exposed outside of the endoscope 1904near the papillae 1990. The distal end 1926 of the cutting wire may bedistally advanced relative to the distal end 1928 of the catheter untilit contacts the papillae 1990.

The cutting wire may be electrically coupled to an active port of apower source, such as an ESU unit (see FIGS. 1 and 3), and theconductive portion 1942 and the return wire 1946 may be electricallycoupled to a return port of the power source. The power source may beactivated, which may send electrical current to the distal end 1926 ofthe cutting wire to cut the papillae 1990. After passing through thepapillae 1990, the electrical current may flow or be drawn to theconductive portion 1942, as denoted by the arrows, and then through thereturn wire 1946 back to the power source to complete the circuit path.

An alternative method may include a combined cut and coagulationprocedure. With reference to FIGS. 13 and 19, the electrosurgical system1902 may be configured in a monopolar configuration, which may use aneutral electrode attached to the patient. The method may includeelectrically coupling the cutting wire to the active port of the powersource, while electrically disconnecting the conductive portion 1942 andthe return wire 1946 from the power source. Electrical current may besupplied to the distal end 1926 of the cutting wire to perform thecutting, such as to cut the papillae. In the event of bleeding orexcessive bleeding, an operator of the electrosurgical system 1902 maydetermine to coagulate the bleeding tissue, in which case the method ofoperation may further include changing or switching a position of aswitch (FIG. 13) so that the conductive portion 1942 is electricallycoupled to the power source and the cutting wire is electricallydisconnected. The endoscope 1904 may be repositioned so that theconductive portion 1942 is contacting the bleeding portion of thetissue. The power source may then be activated at a coagulation settingto perform the coagulation.

The above described electrosurgical procedure is not limited to asphincterotomy, and the electrosurgical systems described with referenceto FIGS. 1-19 may have other similar methods of operation to performother electrosurgical procedures, where sufficient contact is madebetween tissue and a conductive portion of an outer surface of anendoscope or other types of medical delivery devices to perform theelectrosurgical procedures.

The foregoing description of various embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the preciseembodiments disclosed. Numerous modifications or variations are possiblein light of the above teachings. The embodiments discussed were chosenand described to provide the best illustration of the principles of theinvention and its practical application to thereby enable one ofordinary skill in the art to utilize the invention in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally, and equitably entitled.

1. A bipolar electrosurgical system configured to perform anelectrosurgical procedure at a treatment site within a patient, theelectrosurgical system comprising: an electrosurgical device; and amedical delivery device configured to deliver a distal end of theelectrosurgical device to the treatment site, wherein theelectrosurgical device comprises an active member that is configured aspart of an active path for the bipolar electrosurgical system; whereinthe medical delivery device comprises a conductive portion that is atleast one of disposed on or integral with an outer surface of themedical delivery device, the conductive portion configured as part of areturn path for the bipolar electrosurgical system.
 2. The bipolarelectrosurgical system of claim 1, wherein the medical delivery devicecomprises an endoscope.
 3. The bipolar electrosurgical system of claim1, wherein the conductive portion comprises conductive ink.
 4. Thebipolar electrosurgical system of claim 1, wherein the conductiveportion comprises conductive tape.
 5. The bipolar electrosurgical systemof claim 1, further comprising a removably attachable return electrodethat comprises the conductive portion.
 6. The bipolar electrosurgicalsystem of claim 5, wherein the removably attachable return electrodecomprises a sleeve.
 7. The bipolar electrosurgical system of claim 5,wherein the removably attachable return electrode comprises a cap. 8.The electrosurgical system of claim 1, further comprising a return wireelectrically coupled to the conductive portion.
 9. The electrosurgicalsystem of claim 8, wherein the return wire longitudinally extends withina tubular member of the medical delivery device.
 10. The electrosurgicalsystem of claim 8, wherein the return wire longitudinally extendsexternal to a tubular member of the medical delivery system.
 11. Theelectrosurgical system of claim 1, wherein the electrosurgical devicehas a monopolar configuration.
 12. A method of performing anelectrosurgical procedure using a bipolar configuration, the methodcomprising: delivering an outer tubular member of a medical deliverydevice to a treatment site within a patient, the medical delivery devicecomprising a conductive portion that is at least one of disposed on orintegrated with an outer surface of the tubular member the medicaldelivery device, and a working channel longitudinally extending withinthe outer tubular member of the medical delivery device; contacting areturn electrode to a first tissue portion of the patient when a distalportion of the medical delivery device is positioned at the treatmentsite; delivering an electrosurgical device within the working channel ofthe medical delivery device to the treatment site, the electrosurgicaldevice comprising an inner tubular member and an active member disposedwithin the inner tubular member; contacting a distal end of the activemember of the electrosurgical device with a second tissue portion;electrically coupling the active member of the electrosurgical device toan active port of a power source; electrically coupling the conductiveportion of the medical delivery device to a return port of the powersource; activating the power source to supply electrical current to thetreatment site.
 13. The method of claim 11, further comprising: drawingcurrent to the conductive portion to send current along a return pathback to the power source.
 14. The method of claim 12, wherein the firsttissue portion comprises an inner wall of a pylorus.
 15. The method ofclaim 12, wherein the electrosurgical procedure comprises asphincterotomy and the second portion comprises a papillae.
 16. Anendoscope configured to operate in a bipolar electrosurgical system, theendoscope comprising: an elongate tubular member comprising an outersurface; a working channel lumen longitudinally extending within theelongate tubular member, the working channel lumen configured to have anelectrosurgical device movably disposed therein; at least oneillumination lumen having illumination fibers disposed therein, theillumination fibers configured to illuminate a treatment site forvisualization using the endoscope; and a conductive portion that is atleast one of disposed on or integral with the outer surface of theelongate tubular member, the conductive portion configured for contactwith tissue to perform an electrosurgical procedure using a bipolarconfiguration.